WARNING in brd_probe

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4938296e03bd Linux 4.19.198
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1109eba2300000
kernel config: https://syzkaller.appspot.com/x/.config?x=9013c716691ad1fe
dashboard link: https://syzkaller.appspot.com/bug?extid=dd978d5cad6251a8251c
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=134255cc300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=17b7d8b2300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dd978d...@syzkaller.appspotmail.com

RDX: 0000000000000012 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000002 R09: 00007ffffe6d39c8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffffe6d383c
R13: 431bde82d7b634db R14: 00000000004ae018 R15: 0000000000400488
------------[ cut here ]------------
WARNING: CPU: 1 PID: 354 at block/genhd.c:719 __device_add_disk.cold+0x69/0x188 block/genhd.c:719
Kernel panic - not syncing: panic_on_warn set ...

CPU: 1 PID: 354 Comm: syz-executor303 Not tainted 4.19.198-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
panic+0x26a/0x50e kernel/panic.c:186
__warn.cold+0x20/0x5a kernel/panic.c:541
report_bug+0x262/0x2b0 lib/bug.c:183
fixup_bug arch/x86/kernel/traps.c:178 [inline]
fixup_bug arch/x86/kernel/traps.c:173 [inline]
do_error_trap+0x1d7/0x310 arch/x86/kernel/traps.c:296
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1038
RIP: 0010:__device_add_disk.cold+0x69/0x188 block/genhd.c:719
Code: 02 84 c0 74 08 3c 03 0f 8e a8 00 00 00 44 8b a5 b8 05 00 00 e9 75 29 6b fb e8 13 bb 66 f9 48 c7 c7 20 72 b2 88 e8 1d 76 f7 ff <0f> 0b e9 9d 35 6b fb e8 fb ba 66 f9 48 c7 c7 20 72 b2 88 e8 05 76
RSP: 0018:ffff88808e0af700 EFLAGS: 00010282
RAX: 0000000000000024 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff814dfcf1 RDI: ffffed1011c15ed2
RBP: ffff88809ec44600 R08: 0000000000000024 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88809ec44690
R13: ffff88809ec44c58 R14: 00000000fffffff4 R15: ffff88809ec44604
add_disk include/linux/genhd.h:409 [inline]
brd_init_one drivers/block/brd.c:434 [inline]
brd_probe+0x1bd/0x3a0 drivers/block/brd.c:456
kobj_lookup+0x268/0x460 drivers/base/map.c:124
get_gendisk+0x48/0x380 block/genhd.c:856
bdev_get_gendisk fs/block_dev.c:1080 [inline]
__blkdev_get+0x461/0x1480 fs/block_dev.c:1473
blkdev_get+0xb0/0x940 fs/block_dev.c:1627
blkdev_get_by_dev+0x3b/0x70 fs/block_dev.c:1752
swsusp_check+0x4d/0x280 kernel/power/swap.c:1516
software_resume+0x1c6/0x390 kernel/power/hibernate.c:870
resume_store+0xf9/0x130 kernel/power/hibernate.c:1072
kobj_attr_store+0x50/0x80 lib/kobject.c:811
sysfs_kf_write+0x110/0x160 fs/sysfs/file.c:140
kernfs_fop_write+0x2b0/0x470 fs/kernfs/file.c:316
__vfs_write+0xf7/0x770 fs/read_write.c:485
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x447be9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 17 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffffe6d3828 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000077d54 RCX: 0000000000447be9
RDX: 0000000000000012 RSI: 0000000020000140 RDI: 0000000000000004
RBP: 0000000000000000 R08: 0000000000000002 R09: 00007ffffe6d39c8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffffe6d383c
R13: 431bde82d7b634db R14: 00000000004ae018 R15: 0000000000400488
Kernel Offset: disabled
Rebooting in 86400 seconds..


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